sourcemap

Documentation

Overview

Package sourcemap maps positions in emitted Go back to .gpp source.

Because emission is text-edit-based (intra-line splices plus inserted header/marker lines) and then gofmt-formatted, a line-level diff between source and output recovers an accurate mapping: unchanged lines map exactly, spliced lines map with line fidelity, inserted lines attribute to the nearest preceding mapped line.

Index

• type Map
  • func Build(gppPath string, gppSrc, emitted []byte) *Map
  • func (m *Map) Forward(pos token.Position) (token.Position, bool)
  • func (m *Map) Map(pos token.Position) (token.Position, bool)

Types

type Map

type Map struct {
	GppPath string
	// contains filtered or unexported fields
}

Map maps one emitted file's positions to its .gpp source.

func Build

func Build(gppPath string, gppSrc, emitted []byte) *Map

Build diffs gpp source against emitted output.

func (*Map) Forward

func (m *Map) Forward(pos token.Position) (token.Position, bool)

Forward maps a .gpp position to its emitted counterpart — the inverse direction, built from the same line pairing (the first emitted line attributed to the .gpp line wins; columns carry over on exact lines and clamp to column 1 otherwise). ok is false for .gpp lines with no emitted counterpart.

func (*Map) Map

func (m *Map) Map(pos token.Position) (token.Position, bool)

Map translates an emitted-file position to a .gpp position. ok is false when the line has no plausible source counterpart (e.g. the header).